First things first.
1) Find the folder found in the HOI folder, named "AVI"
2) Right-click on it and select rename. rename it to AVI_back
3) right-click on the windows main desktop, select properties. Then select the settings tab, then you will see a box where you can change the resolution of your desktop and another where you can change the colour depth. Change this to 16BIT. select okay after making the changes.
4) Reboot, then try and play HOI.